The prior art histological tissue freezing apparatus includes a container enclosing a cavity having a selective pressurized fluid such as dichlorodifluoromethane, and a spray means having a non-adjustable flow valve with a button actuator.
One problem with the prior art tissue freezing apparatus is that it causes release of gases which are detrimental to the atmosphere. A further disadvantage is that during successive tissue freezing, and cuttings with a special knife, of tissue specimens, finger fatigue occurs. A still further disadvantage is that it is necessary to stop spraying to change flow rate.